A fossil-calibrated phylogeny reveals the biogeographic history of the Cladrastis Glade, an amphi-Pacific early-branching group in papilionoid legumes
A fossil-calibrated phylogeny reveals the biogeographic history of the Cladrastis Glade, an amphi-Pacific early-branching group in papilionoid legumes
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化石校准的系统发育揭示了 Cladrastis 分支的生物地理学历史，Cladrastis 分支是蝶形豆科植物中的两栖-太平洋早期分支群体
DOI：
10.1016/j.ympev.2019.106673
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发表时间：
2020-02-01
影响因子：
4.1
通讯作者：
Chen, Hong-Feng
中科院分区：
文献类型：
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作者：
Duan, Lei;Harris, A. J.;Chen, Hong-Feng
早期分枝的十字花科豆科植物枝状丛林在东亚和温带美洲有一个有趣的两栖-太平洋间断分布。在这里，我们使用核和三个叶绿体区域来重建枝状林地的系统发育关系和分化时间，以及可能在其生物地理史上起关键作用的形态特征的进化。祖先特征状态估计显示，枝状林地最近的共同祖先是落叶乔木，果实扁平，有翼。据推测，始新世早期，枝状丛林起源于北美洲中纬度的耐热森林，随后有翅果的扁豆与非翅果类群祖先的分裂，以及后来枝状丛林的分化。来自始新世中期的非翅果群。Platyospron和Cladrastis S.S.显示出“北美洲以外”的生物地理格局，可能在始新世中晚期通过白令大陆桥(BLB)或北大西洋大陆桥(NALB)迁移到亚洲。我们的结果，再加上对沼泽地相对较好的化石记录，表明Platyosprion在北美经历了一次物种灭绝事件，这是始新世-渐新世转变前后气候变冷导致的，这推动了北美西部的主要植被转变，反过来又成为Pickeringia和Styphnolobium更替的障碍。前者的灌木状习性和硬叶的演化可能与北美西南部的查帕尔植被相适应；后者获得了念珠状、肉质果实的特征。渐新世，Styphnolobium进一步向南扩散到热带北美，中中新世通过BLB向东扩散到亚洲。随后BLB的分裂促进了圣阿菲娜和圣日本斯的更替。
The early-branching Cladrastis Glade of papilionoid legumes (Leguminosae, Papilionoideae) has an intriguing amphi-Pacific disjunct distribution in eastern Asia and temperate-tropical Americas. Here we used nuclear and three plastid regions to reconstruct the phylogenetic relationships and divergence times in the Cladrastis Glade, as well as the evolution of morphological characters that might have been key in its biogeographic history. The ancestral character state estimation revealed that the most recent common ancestor of the Cladrastis Glade was deciduous trees possessing compressed, winged fruits. The Cladrastis Glade was inferred to have originated in the mid-latitude thermophilic forests of North America in the early Eocene, followed by the split between ancestors of wing-fruited Platyosprion and the non-wing-fruited group, and later the divergence of Cladrastis s.s. from the non-wing-fruited group in middle Eocene. Platyosprion and Cladrastis s.s. display an "out-of-North-America" biogeographic pattern and might have migrated to Asia via the Bering land bridge (BLB) or the North Atlantic land bridges (NALB) during middle to late Eocene. Our results, coupled with the relatively well documented fossil record for the Glade, suggest that Platyosprion experienced an extinction event in North America caused by climatic cooling around the Eocene-Oligocene transition, which drove a major vegetation shift in western North America, in turn serving as a barrier for the vicariance of Pickeringia and Styphnolobium. The evolution of shrubby habit and sclerophyllous leaves in the former might be adaption to the chaparral vegetation in southwestern North America; the latter gained the trait of moniliform, succulent fruit. Styphnolobium further dispersed southward to tropical North America in the Oligocene, and eastward to Asia through BLB during middle Miocene. Subsequent sundering of BLB facilitated the vicariance of St. affine and St. japonicum.